Reversible ratchet wrenches have long been known in the art and are very familiar to automobile mechanics and other operators who have need to work with mechanical machinery. Since the first reversible ratchet wrench was invented, numerous improvements have heen made for accomplishing the reversing function of the ratchet wrench such as shown in the patents to J. S. Dodge, U.S. Pat. Nos. 2,003,346 and 2,590,587, as well as to Garofalo and Tracy, U.S. Pat. Nos. 4,300,413 and 4,277,989, respectively. The first patents to Dodge disclose reversible ratchet wrenches wherein two ratchet wheel engaging pawls are utilized on opposite sides of the ratchet wheel, one or the other to engage the wheel depending upon choice of rotation direction. The latter two patents to Garofalo and Tracy utilize a double-ended pawl which is maneuvered against the ratchet wheel by manual manipulation of a control rod connected to the pawl.
In addition, Applicant was previously awarded U.S. Pat. No. 4,445,404 for a reversible ratchet wrench employing a reversing push button with an attached ramp with which a control or extension rod co-acts, the other end of which is attached to the double-ended pawl. For selecting ratchet direction, the push button is depressed which causes the attached ramp to push the extension rod linearly and thus rotate the pawl into engagement with the ratchet wheel. A spring engaging the extension rod causes the extension rod to pivot the double-ended pawl to the opposite side of the ratchet wheel when the ramp is removed. Applicant's prior invention suffers fom the problem that the end of the extension rod engaging the ramp attached to the push button has a tendency to stick and catch when being operated. The application of lubricant improves the operation of the reversible wrench, however, as the lubricant is worn off, or washed away, the wrench tends to return to its prior condition of sticking or catching such as to make manipulation of the push button rather hard and difficult at times.
The desirability of a push button operated reversible mechanism near the handle of a ratchet wrench is obvious since the operator or mechanic, in grasping the handle and without removing his hand or moving his hand and utilizing his thumb or forefinger, may reverse the direction of the ratchet wrench. However, there is need for a push button type reversible ratchet wrench that provides reliable reversing action where potential problems of the mechanism hanging up or catching is avoided.